Potter added that the halting of the sale also took the pressure off the RBS consortium which had been urged to beat Bank of America's price for LaSalle under a 'go shop' clause which expires on Sunday. He said: 'It gives them breathing space to put their offer to Dutch shareholders.'

The Amsterdam-based group faced attacks from its shareholders over efforts to block the rival and last week opened its books to the RBS team, which also includes Belgian bank Fortis and Spain's Santander.

It also dropped a 'stand-still' clause preventing the the rival bidder from making a hostile bid for the firm for a year.

If the RBS team wins control of the Dutch bank, it plans to break the company up, with Fortis taking its banking operations in Holland and Belgium, and Santander the Latin American businesses and Italian bank Antonveneta. RBS is eyeing LaSalle and ABN's Asian business.

Barclays has agreed to move its headquarters to Amsterdam as part of the proposed merger. The duo have announced plans to cut 12,800 jobs from the combined 217,000 workforce, with another 10,800 positions likely to be transferred to lower-cost locations. Barclays and RBS were unavailable for comment following today's ruling.